In fluid engineering, valve units are used to influence the fluid flow selectively. This is the case, for example, of influencing the pressurization of a fluidically activated drive element, which in turn can be used, for example, to actuate a shutoff organ. In this connection, multi-way valve units with three ports are used for various applications, wherein typically one port—depending on the switched position of the multi-way valve unit—is in fluidic communication with one and/or other of the two remaining ports or else can be shut off relative to the other two ports. It is not only slide valves with such a function that are known, especially such in which a single slide, which can be displaced within a valve housing containing the three ports and which—depending on its position—opens or shuts off the said fluid communication paths. To the contrary, three-way valve units are also known that have a valve group comprising two structurally independent single valves, wherein the two single valves of the valve group can be actuated by means of an actuating device and typically one of three ports is in fluidic communication both with a valve chamber of the one single valve and also with a valve chamber of the other single valve (see EP 2133546 A1). In a particular manner—other than that according to EP 2133546 A1—these two single, valves can be biased in such a way that the one single valve—without pressurization of an actuator associated therewith—assumes a closed position, while the other single valve—without pressurization of an actuator associated therewith—assumes an open position.
The object of the present invention is to provide a regulated proportional three-way valve unit having the features indicated in the introduction, characterized by a high degree of operating safety and reliability as well as by good regulation behavior in combination with a relatively simple design structure.